Re: Stolen and degraded time and schedulers

From: Jeremy Fitzhardinge
Date: Wed Mar 14 2007 - 17:43:22 EST


Daniel Walker wrote:
> It's used for measuring execution time, but timers are triggered based
> on that time, so it needs to be actual execution time. I don't know to
> what extent this is already inaccurate on some system tho.
>

Well, "actual execution time" is a bit ambiguous: should that be "time
actually spent executing", or "time we should have spent executing"?

It looks like cpu_clock_sample() will only return accurate results on
yourself; if you get the sched_ns on a thread on another cpu, it won't
include the time accumulated since the start of its timeslice.

J

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